The height read-only property of the SVGFEBlendElement interface describes the vertical size of an SVG filter primitive as a SVGAnimatedLength.
It reflects the <feBlend> element's height filter primitive attribute. The attribute is a <length> or a <percentage> relative to the height of the filter region. The default value is 100%. The property value is a length in user coordinate system units.
The <feBlend> SVG filter blends two input images together using commonly used imaging software blending modes.
const feBlend = document.querySelector("feBlend");
const verticalSize = feBlend.height;
console.log(verticalSize.baseVal.value); // the `height` valueSVGFEBlendElement.width<blend-mode> data typemix-blend-mode property